Fabric edge curler member for a paper machine

ABSTRACT

A curling member for curling the outside edge of a forming fabric in a paper making machine. The curling member is detachably secured to a support member located under the outside edge of the forming fabric. The curling member has a fabric support surface having a lower end lying below the horizontal plane of the fabric and curving upwardly outward a distance sufficient to support and impart an upward curvature to a portion of the edge of the forming fabric.

United States Patent 91 Hansen 2 FABRIC EDGE CURLER MEMBER FOR A PAPER MACHINE [76] Inventor: Victor Emanuai Hansen, 7704 Wildwood Way, Jacksonville, Fla. 32216 22 Filed: Feb. 19,1974

21 Appl. No.: 443,735

[52] US. Cl. 162/274; 162/354; 162/374 [51] Int. D211 H24 [58] Field of Search 162/354, 374, 353, 352, 162/351, 348, 274, 273, 211, 199;

[56] References Cited UNITED STATES PATENTS Hayward..

[ 1 Dec. 23, 1975 2,094,350 9/1937 Cartigny 210/401 2,314,294 3/1943 Wallny 210/401 3,337,394 3/1967 White et a]. 162/352 Primary ExaminerS. Leon Bashor'e Assistant ExaminerRichard V. Fisher [57] ABSTRACT A curling member for curling the outside edge of a forming fabric in a paper making machine. The curling member is detachably secured to a support member located under the outside edge of the forming fabric. The curling member has a fabric support surface having a lower end lying below the horizontal plane of the fabric and curving upwardly outward a distance sufficient to support and impart an upward curvature to a portion of the edge of the forming fabric.

9 Claims, 10 Drawing Figures U.S. Patent Dec. 23, 1975 Sheet 1 of2 3,928,124

direction of Fabflc 5 7 I 9'3 5% 53 5/ Z r /1 .54 /6 FIG 4b US. Patent Dec. 23, 1975 Sheet 2 of2 3,928,124

FABRIC EDGE CURLER MEMBER FOR A PAPER MACHINE BACKGROUND OF INVENTION a. Field of the Invention This invention relates to Fourdrinier paper making machines and more particularly to easily detachable edge curler members to take the place of the deckle boards on these machines. Deckle boards have been widely used on all types of Fourdrinier machines to prevent wet stock on the forming fabric, or wire, from flowing off at the edges before sufficient water has been removed from the stock to render it self-supporting.

b. Description of Prior Art In paper making machines heretofore known, a deckle board is placed near each edge of the forming fabric extending from just upstream of the location where the stock first contacts the fabric to a point downstream where the stock which is forming a sheet ceases to flow as a liquid. Since the deckle boards must make contact with the fabric in order to control lateral spreading of wet stock, wear will occur on the fabric under the deckle boards, particularly in the locations where the fabric travels over dewatering elements such as table rolls or stationary foils. This wear can be minimixed by providing a relatively soft material like rubber at the bottom edges of the boards and by very careful alignment. Usually, however, the deckle board mounting structures are not equipped with means to accomplish accurate alignment and very often, to ensure proper restraint of the stock, the boards are installed so that they bear downwardly too heavily, thus causing severe damage to the delicate forming fabric.

Another disadvantage inherent in deckle boards is that the rapidly moving liquid stock tends to rise up against the stationary inner surfaces of the boards and then flow back at reduced speed, thus causing diagonal waves to be formed in the stock which results ultimately in undesirable variations in the thickness in the sheet of paper. This disadvantage was overcome in the early history of Fourdrinier machines by using travcl ling endless deckle straps which rested on the surface of the forming fabric and moved at the same speed over the critical area. Travelling deckle straps reduce the wear on the top surface of the fabric but as machines ran faster they were impracticable because of centrifugal force effects. Furthermore, the running mechanism for the travelling straps is large and unwieldy and not well suited for use on the high speed paper machines.

It has been previously found that if the edges of the forming fabric are curled upwardly a small amount in the area where the stock is liquid. the lateral flow of stock is restricted by the up-curl and the deckle boards with all their attendant difficulties can be removed. Furthermore, with the more widespread use of synthctic fabrics, which are not as susceptible to fatigue cracking as those woven of metals such as bronze, brass or stainless steel, the idea of up-curling the edges of the fabric to replace deckle boards has become more feasible. Since it is not practical to attempt to build into the fabric up-curled edges of given proportion, it has been the practice to attach small deflectors to the machine frame under the edges of the fabric to raise the edges of the fabric at several locations in the wet zone. The number and position of edge curling deflectors installed depends upon the type of fabric and machine operating conditions. Normally a sufficient number of 2 deflectors will be placed to effectively curl the edges of the wire to confine the stock as it travels from the forming board almost to the wet line.

SUMMARY OF INVENTION From a broad aspect, the present invention provides a curling member for curling the outside edge of a forming fabric in a paper making machine. The curling member is detachably secured to a support member located under the outside edge of the forming fabric. The curling member has a fabric support surface hav ing a lower end lying at the level ofor slightly below the horizontal plane of the fabric and curving upwardly outward a distance sufficient to support and impart an upward curvature to a portion of the edge of the forming fabric.

In the present invention use is made of the T-bar foil attachment which has gained wide popularity in the paper making industry and offers a simple and versatile method of curling the edges of a fourdrinier wire or fabric to meet the particular operating requirements of any stock on any fourdrinier paper machine equipped with T-bar foils. In the preferred embodiment of the invention, the fixed or adjustable deflectors used to curl the edges of the fabric are replaced by edge curling guide forms made of any suitable rigid material. The forms are provided with a T-shaped recess in the bottom so that they may be slid into position on a T-bar foil rail at each side of the paper machine. The T-recess in a guide form is made to fit snugly on the T-rail so that when the form is slid into the desired position, it will remain in that position. As a further security measure to prevent undesirable displacement, the forms may be locked in position by any known method such as employing set screws or simply a wedge.

The edge curling forms may be installed on T-rails in abutment with the ends of foil blades that have been shifted so that the forms will engage the edge of the fabric, or, on spare T-rails, that are not at the time being used to hold foil blades. As a more permanent measure, the edge curling forms may be installed on short sections of T-rails provided specifically for the purpose and fastened to the paper machine side rails or to the T-rail support structure for the foils.

In the other embodiments of the invention the end section of a regular foil blade may be modified so that the support surface underneath the edge of the forming fabric can be raised to provide the required amount of upward curl.

BRIEF DESCRIPTION OF DRAWINGS The invention will now be described with reference to preferred embodiment modifications which are illustrated in the accompanying drawings in which:

FIGS. Ia and lb are side and end views, respectively, of a curling guide member;

FIGS. 20 and 2!) are side and end views, respectively, of a further curling guide member;

FIGS. 30 and 3h are side and end views, respectively, of a further curling guide member;

FIG. 4a is a side view ofa further curling guide member;

FIG. 4b is a crosssection view along cross-section lines l-l of FIG. 4a; and

FIGS. 5a and Share perspective views illustrating the manner in which two of the embodiments of the invention are mounted on a paper machine.

DESCRIPTION OF PREFERRED EMBODIMENTS FIGS. 1 4 show side and end elevations of four adaptations of a T-bar foil attachment generally shown at 10, which constitute the main embodiments of this invention. The end elevations are viewed from the centre line of a paper machine outwardly toward the side of the machine. In FIGS. la and lb the forming fabric 20 is shown with its edge 21 curled upward in passing over the curling guide member 11. The guide member II is provided with a tight fitting T-recess I2 in its bottom surface I3 so that it can be forcibly slid on the end of a support member, herein a T-rail l5 and having shoulders 16, as illustrated, and positioned as required to cause the desired up-curl in the edge of the fabric 20. The guide member 11 will remain in position since there is very little force exerted by the edge 21 of the fabric which might cause it to move transversely to the direction of movement of the fabric. The shape of the upper curved support surface 14 over which the edge of the fabric travels is made to suit the required conditions of the machine. For example, the lower end or edge 17 of the curved surface 14 should lie at the level of or slightly below the plane of the fabric 20 and the upwardly curved surface 14 should be such that from 2 to 4 inches, approximately, at the outside edge of the fabric, will be curled upwardly along a gentle slope so that the outer edge 22 of the fabric is raised upwardly from about A inch to about 3 inches from the horizontal plane of the fabric depending on the stock conditions prevailing.

FIGS. 2a and 2b show the adaptation of a regular T-bar foil 30 modified and positioned on the T-rail so as to cause the edge 21 of the fabric to curl upward. In this adaptation a cut 31 is made part way through the foil blade from the bottom side 32 at approximately 4 inches from the end 33. When the blade 30 is slid on the T-rail 15, the overhang portion 34 beyond the cut is bent upwardly so that the bottom side 32 of the flanges of the blade 30 rest on the shoulders 16 of the T-bar 15 to form an integral curling member 37. The blade 30 is then positioned to induce the desired up-curl in the edge 21 of the fabric 20.

FIGS. 3a and 3b show another modification of a regular foil blade 40. In this case. a horizontal cut 41 is made about 3 or 4 inches into the end of the blade a short distance below the top surface 42 thereof and a wedge block 43 is placed so as to form a separation in the cut 41 and thus elevate the top surface 42 to form an integral curling member 47. The wedge block 43 may be fixed in position by means of a screw 44 countersunk in the upper surface 45 of the recess 46 of the foil blade 40 as shown,

FIGS. 44 and 41) show yet another modification of a foil blade 50 in which horizontal and vertical cuts, 51 and 52 respectively, are made at the end of the blade 50 to form a flap 53 which may be bent upward. The flap 53 is held in position by means of a wedge shaped block 54 which has a T-recess 55 in its bottom surface proportioned to fit snugly on the T-rail 15. Thus, there is formed an integral edge curling member 57 in the end of the blade 50.

To effectively curl the edges 21 of the fabric 20 in the wet section of a paper machine, usually more than one curling guide member is required along each edge of the fabric. For the embodiment shown in FIG. I, it is visualized that alternate foil blades will he slid inwardly on the T-rail I5 left and right to leave room on the 4 outside portions of the T-rails for placement of the curling guide member. In the adaptations shown in FIGS. 2, 3 and 4, only one end of the foil blade may be modified and here again alternate foil blades will constitute the edge curling medium at the right and left sides.

In positioning the edge curling member, allowance will be made. to ensure that the horizontal span of the upward curve will exceed the horizontal oscillation of the fabric as it rotates. In any case, the use of an edge curling member or the incorporation of same in the end of a foil blade, will provide a quick, easy and accurate method of curling the edge ofa fabric to form a deckle on those paper machines which are equipped with T-bar foils.

Referring now to FIGS. 5a and 5b, there is shown the position of edge curling members when mounted on a paper making machine. The T-rails 15 are secured to the machine side rails 58 and extend transversely to the direction of movement of the forming fabric as indicated by arrow 59. Hereinshown, member II illustrates the embodiment of F IG. 1 whilst member 40 illustrates the embodiment of FIG. 3. In FIG. 5b, the edge curling member 11 of FIG. I is shown slidingly retained on a short section of T-rail 15' secured to the machine side rail 58.

As more clearly illustrated in FIGS. 50 and 5b, the curved fabric support surface 14 is substantially flat and has rounded side edges 60 extending transversely to the direction of travel of said forming fabric.

I claim:

I. A curling member for curling the outside edge of a forming fabric of a paper making machine with said fabric supported on foil blades mounted on support rails, said curling member having an upper, substantially flat fabric support surface, said fabric support surface having rounded side edges extending transversely to the direction of travel of said forming fabric, said support surface having a lower end lying at the level of or slightly below the horizontal plane of said fabric and curving upwardly outward a distance sufficient to support and impart an upward curvature to a portion of the outside edge of said forming fabric, and a recess in an underface of said curling member for tight sliding fit of said curling member on an end portion of a respective one of said support rails, said sliding fit providing adjustment of said curling member transversely to the axis of travel of said fabric to obtain a desired up-curl in a side edge of said fabric.

2. A curling member as claimed in claim 1 wherein said recess is of T-shaped cross-section, said rail having shoulders on each side of an upper end thereof for engagement with said recess.

3. A curling member as claimed in claim 1 wherein said flat support surface is upwardly curved a distance sufficient so that the outside edge of the fabric will be curled upwards along a width of from 2 to 5 inches.

4. A curling member as claimed in claim 1 wherein said curling member is in tight sliding fit on an end portion of an auxiliary short section of a support rail.

5. A curling member as claimed in claim 1 wherein a pair of said curling members is secured under opposed side edges of said fabric with each curling member in sliding fit with a respective alternate one of said support rails.

6. A curling member as claimed in claim 5 wherein said curling member is formed integrally in at least one end of one of said foil blades, said flat fabric support surface being constituted by bending upwardly the said one end whereby the upper surface of the foil blade will provide said flat support surface.

7. A curling member as claimed in claim 6 wherein said curling member is formed by providing a cut part way through said foil blade from a bottom side thereof at a predetermined distance from said at least one end of said foil blade. said cut facilitating bending of said end of said foil blade and providing for the bottom edge of said end to rest on said support member.

8. A curling member as claimed in claim 6 wherein said curling member is formed by providing a horizontal cut from said at least one end and extending a predetermined distance under said upper surface of said foil, 21 wedge secured under said at least one end and 6 having a sloping upper surface to elevate said upper surface of said foil at said end 9. ln a paper machine having a forming fabric for supporting wet stock deposited thereon to form a sheet of paper, said machine having at least a plurality of drainage foils supported under said fabric on support rails, said fabric being supported on an upper surface of said foils and in contact with at least a leading edge of said foils, the improvement comprising a plurality of curling members as defined in claim 5 positioned on each side of said fabric in a region immediately downstream where said wet stock is deposited on said fabric whereby to impart said upcurl in the edges of said fabric along said region for the purpose of confining wet stock thereon. 

1. A CURLING MEMBER FOR CURLING THE OUTSIDE EDGE OF A FORMING FABRIC OF A PAPER MAKING MACHINE WITH SAID FABRIC SUPPORTED ON FOIL BLADES MOUNTED ON SUPPORT RAILS, SAID CURLING MEMBER HAVING AN UPPER, SUBSTANTIALLY FLAT FABRIC SUPPORT SURFACE, SAID FABRIC SUPPORT SURFACE HAVING ROUNDED SIDE EDGES EXTENDING TRANSVERSELY TO THE DIRECTION OF TRAVEL OF SAID FORMING FABRIC, SAID SUPPORT SURFACE HAVING A LOWER END LYING AT THE LEVEL OF OR SLIGHTLY BELOW THE HORIZONTAL PLANE OF SAID FABRIC AND CURVING UPWARDLY OUTWARD A DISTANCE SUFFICIENT TO SUPPORT AND IMPART AN UPWARD CURVATURE TO A PORTION OF THE OUTSIDE EDGE OF SAID FORMING FABRIC, AND A RECESS IN AN UNDERFACE OF SAID CURLING MEMBER FOR TIGHT SLIDING FIT OF SAID CURLING MEMBER ON AN END PORTION OF A RESPECTIVE ONE OF SAID SUPPORT RAILS, SAID SLIDING FIT PROVIDING ADJUSTMENT OF SAID SURLING MEMBER TRANSVERSELY TO THE AXIS OF TRAVEL OF SAID FABRIC TO OBTAIN A DESIRED UP-CURL IN A SIDE EDGE OF SAID FABRIC.
 2. A curling member as claimed in claim 1 wherein said recess is of T-shaped cross-section, said rail having shoulders on each side of an upper end thereof for engagement with said recess.
 3. A curling member as claimed in claim 1 wherein said flat support surface is upwardly curved a distance sufficient so that the outside edge of the fabric will be curled upwards along a width of from 2 to 5 inches.
 4. A curling member as claimed in claim 1 wherein said curling member is in tight sliding fit on an end portion of an auxiliary short section of a support rail.
 5. A curling member as claimed in claim 1 wherein a pair of said curling members is secured under opposed side edges of said fabric with each curling member in sliding fit with a respective alternate one of said support rails.
 6. A curling member as claimed in claim 5 wherein said curling member is formed integrally in at least one end of one of said foil blades, said flat fabric support surface being constituted by bending upwardly the said one end whereby the upper surface of the foil blade will provide said flat support surface.
 7. A curling member as claimed in claim 6 wherein said curling member is formed by providing a cut part way through said foil blade from a bottom side thereof at a predetermined distance from said at least one end of said foil blade, said cut facilitating bending of said end of said foil blade and providing for the bottom edge of said end to rest on said support member.
 8. A curling member as claimed in claim 6 wherein said curling member is formed by providing a horizontal cut from said at least one end and extending a predetermined distance under said upper surface of said foil, a wedge secured under said at least one end and having a sloping upper surface to elevate said upper surface of said foil at said end.
 9. In a paper machine having a forming fabric for supporting wet stock deposited thereon to form a sheet of paper, said machine having at least a plurality of drainage foils supported under said fabric on support rails, said fabric being supported on an upper surface of said foils and in contact with at least a leadIng edge of said foils, the improvement comprising a plurality of curling members as defined in claim 5 positioned on each side of said fabric in a region immediately downstream where said wet stock is deposited on said fabric whereby to impart said up- curl in the edges of said fabric along said region for the purpose of confining wet stock thereon. 